TY - RPRT TI - Self-study manual on optical radiation measurements : Part I--Concepts, Chapters 7, 8, and 9 AU - Nicodemus, Fred E PY - 1979 PB - National Bureau of Standards CY - Gaithersburg, MD SN - NBS TN 910-4 DO - 10.6028/NBS.TN.910-4 ER -